This invention relates generally to apparatus for abrasive sanding and particularly to handheld or manual sanding tools.
For many years, industries such as automobile body work and repair have relied heavily upon the use of abrasive sanding apparatus to obtain the desired shaping and surface qualities upon the finished product. While initially the work of sanding and shaping the automobile bodies relied heavily upon burdensome hand or manual sanding, the advent of power-driven sanders such as electric or pneumatic powered devices substantially reduced the amount of burdensome and labor intensive hand sanding carried forward. However, despite the steady improvement of power sanding apparatus, a substantial portion of the typical automobile body repair and shaping remains optimally performed using manual or hand sanding.
The primary tool employed in much of the hand sanding operations is known generally in the art as a xe2x80x9csanding blockxe2x80x9d. While the design and fabrication of sanding blocks has been subject to substantial variation, all typical sanding blocks include the common elements of a hand block or grip, a work surface which is often flat and rectangular, a quantity of abrasive sand paper, sheets or strips and a mechanism for securing the sandpaper upon the work surface.
Not surprisingly, the continuing use of hand sanding apparatus and the continuing need for improved sanding blocks has prompted practitioners in the art to develop a virtually endless variety of sanding blocks. For example, U.S. Pat. No. 6,062,966 issued to Ali et al. sets forth a SANDING BLOCK having a generally rectangular body supporting a curved generally cylindrical hand grip. The body and grip are joined at a center transverse rib and are separated by a gap therebetween. Within the gap, apparatus such as pointed shafts much like the end of conventional nails are supported and extend through the gap. The sanding block is formed of a resilient flexible material such as rubber or plastic allowing the cylindrical grip portion to be deformed away from the gap during the attachment of a sandpaper sheet. When attached, the sandpaper sheet extends across the work surface with the end portions curling upwardly and into the gap to be secured in place by the pointed shafts.
U.S. Pat. No. 5,863,243 issued to Ali forms the parent patent for the above described U.S. Pat. No. 6,062,966 and discloses a SANDING BLOCK which is substantially identical to the above described sanding block. The functional difference of the sanding block in U.S. Pat. No. 5,863,243 is provided by an intermediate portion which is interposed between the curved or cylindrical grip member and the working block portion.
U.S. Pat. No. 5,245,797 issued to Milkie sets forth a MANUAL SNDER having a block for holding a sheet of sandpaper and a housing which may be attached to the block. The block defines two ridges each with a convex top surface. The two ridges are proximate opposed sides of the block and a shaft projects from the block inwardly and adjacent to each ridge. An inverted box-shaped member associated with each ridge defines an elongated slot which receives the shaft such that the box member is able to secure the sandpaper sheet.
U.S. Pat. No. 5,512,010 issued to Labad, Jr. sets forth a WET SANDING BLOCK having a sanding block and a work surface formed on the underside thereof. The work surface supports a sheet of wet for dry sand paper and a pair of end clips for securing the end portions of the sandpaper to the block. The interior of the block defines a hollow chamber within which a plurality of apertures are formed to facilitate downward flow downwardly to the working surface and the sandpaper sheet. A flexible hose is joined to the block in communication with a supply of water under pressure.
U.S. Pat. No. 5,383,308 issued to Beloff et al. sets forth a SANDING BLOCK formed of two block portions which are joined by a spring mechanism. The spring mechanism urges the two block portions outwardly toward an extended position. An endless belt of abrasive sandpaper encircles the block members and is maintained in tension by the spring expanders.
U.S. Pat. No. 5,172,524 issued to Poss sets forth a SANDING BLOCK having a rectangular housing supporting a supplementary block housing and an expanding spring-driven attachment therebetween. An endless belt of sandpaper encircles the housing and supplemental block member which is maintained in tension by the spring-driven expander.
U.S. Pat. No. 4,478,011 issued to Russell sets forth a HAND SANDER having a sanding block structure which includes storage means for an elongated strip of abrasive material. The sander includes a pusher for driving a portion of the abrasive strip over a work piece wherein the storage means for the abrasive strip and the working surface are carried on a cassette structure which is readily separable as a unit from the pusher.
U.S. Pat. No. 4,249,349 issued to Rueb sets forth an ELONGATE SANDING BLOCK having a handle portion from which an elongate support portion projects. The support portion includes means for adherence of a strip of pressure-sensitive adhesive-coded finishing material. The support portion has variously shaped surface facets for supporting the finishing material which include a planar surface portion, an arcuate surface portion and an edge portion.
U.S. Pat. No. 5,337,523 issued to Walsh sets forth a UTILITY TOOL having a hand sander which includes a handle and a plurality of interchangeably fitted inserts securable to the handle. The inserts form an exterior surface for supporting sandpaper or the like which is contoured to match a particular surface detail of a vehicle body or other work piece.
U.S. Pat. No. 4,501,096 issued to Lukianoff and a continuation-in-part thereof issued as U.S. Pat. No. 4,640,060 also issued to Lukianoff each set forth a HAND HELD SANDING DEVICE having a block defining a pair of perpendicular planar surfaces together with mutually perpendicular end surfaces and a cylindrical surface completing the block. The cylindrical surface defines an inwardly extending slot which receives the end portions of a sandpaper sheet wrapped around the block such that the sandpaper sheet ends are inserted into the slot.
U.S. Pat. No. 4,887,396 issued to Lukianoff sets forth a DISPOSABLE SANDING DEVICE fabricated of a block of light-weight resilient material capable of substantially retaining its shape under applied sanding pressure which has a relatively permanent abrasive outer surface formed thereon.
While the foregoing described prior art devices have to some extent improved the art and have in some instances enjoyed commercial success, there remains nonetheless a continuing need in the art for ever more improved hand sanding blocks which facilitate the secure attachment and easy removal of sandpaper while providing a comfortable and secure hand grip.
Accordingly, it is general object of the present invention to provide an improved hand sanding block. It is a more particular object of the present invention to provide an improved hand sanding block which facilitates the secure attachment and easy removal of sandpaper or other abrasive sheets. It is a still more particular object of the present invention to provide an improved hand sanding block which is relatively comfortable in the user""s hand while being simultaneously secured in the users grip for ease of use and hand control.
In accordance with the present invention there is provided a sanding block comprising: an elongated hand grip defining a pair of opposed ends, a convex raised portion, a pair of concave portions on each end thereof and a pair of raised ends; an elongated base housing secured to the hand grip and having a pair of angled end surfaces aligned with the opposed ends of the hand grip and having a support surface; a pair of retractable sandpaper clamps supported at the opposed ends each movable between an extended position and a retracted position; and a pair of lever means each operatively coupled to one of the retractable sandpaper clamps for moving the retractable sandpaper clamps between the retracted and extended positions, the lever means each including an over-center latch for securing the retractable sandpaper clamps in the retracted positions.